Fuel-injection device for oil engines



Feb. 17, 1925. 1,526,544

R. HoFsTETTER FUEL INJECTION DEVICE FOR OIL ENGINES Filed May 5, 1920 Patented lelo. l?, i925.

ROBERT HOFSTETTER, 0F CHICAGO, ILLINOIS, ASSIGNOR, BY DIRECT AND MESNE AS- SIGNMENTS, OF THREE-EIGHTHS TO F. C. MANNING, OF NEWARK, NEW JERSEY,

ONE-FOURTH TO ALBERT ERICKSON. AND THREE-EIGHTHS TO CHARLES KRATSCH,

BOTH OF CHICAGO, ILLINOIS.

FUEL-INJECTION DEVICE FOR OIL ENGINES.

Application led May 5, 1920. Serial No. 579,193.

To all 'zc/10m it may concern.:

Be it'known that I, ROBERT Horsrn'rrnu, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, :have invented new and useful Improvements in Fuel-lnjection Devices for `@il Engines, of which the following is a specification.

'lhis invention relates to means for the delivery and. atomization of heavy oils to the combustion chamber of oil burnino engines and consists essentially of a mechanical atomizer and a primary cylinder both attached to the inlet valve and forming a part thereof.

In order to better understand this invention it is necessary to consider the fact that all oils used as engine fuels contain a certain amount of light liydro-carbons, which once separated from the fuel as a whole can readily be ignited. lf this ignition can be forced to 'take place in a- :receptacle which also contains the residue of the oil from which the hydrocarbons have r been separated, it is readily to be seen that the heat of the eXpl-osion of the light hydrocarbons will not only vaporizc but also ignite the residue of the oil, thus giving complete combustion of all the fuel delivered to the receptacle.

'This process of separate priurary ignition and complete combustion is obtained by means illustrated in the accompanying drawing in which- Figure l is a cross section through the upper portion of an engine cylinder showing the invention incorporated thereto. I

lligure 2 is an enlarged sectional view of the intake valve, the stationary bracket, and the bracket extension.

Similar letters refer to similar parts throughout the two views.

'lhe cylinder A, contains the piston B, and is closed on top by the cylinder cover C, this cover is equipped with inlet valve l?, exhaust valve G, which two valves are operated by valve rocker arms D, and L, these in turn being actuated by push rods l, and K, which -receive their motion from a 2 to l camshaft (not shown). Valves F, and Gr, are kept closed by coil springs lil, and l/V, when not actua-ted by the camshaft, push rods, and valve rocker arms.

ln describing the operation of the engine it is assumed that the four stroke cycle engine is being employed and that the piston is just starting down on the intake stroke. Valve l?, is about to be opened by rocker arm D, which is forked and bears on disk T, locked by check nut U. ln moving downward a vacuum is created in the hollow stem of valve F, and fuel drawn in through the hollow stationary extension Y, and bracket J, past check valve lt, which is raised on each downward stroke and prevents the oil from returning to the supply tank which is in connection with entrance V.

is the valve moves downward it unseats itself from the wall Q, of the cylinder cover thereby permitting a charge of air to enter the cylinder 4f. lThis charge of air in passing valve body 3, will be partly diverted through ports U, and enter the primary cylinder l, and expelling through holes l), therefrom any residue remaining of the burned charge of the previous cycle.

l-laving completed the downward stroke the valve will begin t-o move upward under the influence. of coil spring ll, and the following events will take place.

The oil inside the hollow valve stem is prevented from returning' to the fuel tank as check valve Il, closes. As the pressure due to coil spring l-l, increases the small valve 2, mounted in the lower part of the valve body 8, is forced open as much as the distance between the adjusting screw lil, and the bottom of the small valve 2, will permit. 'lhis distance is chosen so that the fuel oil will enter the primary cylinder l, in the form of a spray, thereby saturating 'the air in the primary cylinder with readily ignited oil vapor.A

After valve l?, is seated on walls QJ, the piston l, continues y'to travel upward thereby increasing the air pressure in the combustion chamber 4, and also in the primary cylinder l, because the latter stands in communication with the combustion chamber Il, through the openings l), which are drilled on a slight angle, thus compelling the air which now enters from the Vcombustion chamber, to agitato the fuel oil which may have accumulated at the bottom of primary cylinder l, thereby vaporizing part thereof 'lll and increasing the inflammability of the mixture in the primary cylinder 1.

As 'the air pressure increases the tempera.- ture rises finally to a point where the vapor conta-ined in the primary cylinder 1, ignites which momentarily increases the pressure in the primary cylinder 1, and forces the still unvapo-rized part ofthe fuel oil out into the combustion chamber proper, in which the air now has reached a temperature high enough to complete the combustion of all the fuel oil.

As this final combustion takes place, the temperature and the pressure increase and thisv pressure is transmitted to the piston which by this time has passed its dead center oint and is on the downward stroke. Having completed the downward stroke the exhaust valve (ir opens under the influence of rocker arm L, and push rod I, and permits the burned charge to leave through the passage X.

After the piston B, reaches the uppermost position the exhaust valve X, closes and the cycle described repeats itself.

The stop cock S, serves to regulate the amount of fuel to be fed into the primary cylinder and may be connected with a suitable centrifugal governor, thereby making the regulation of the engine automatic.

I am aware that prior to my invention fuel injection devices for oil engines have been made with primary cylinders and I therefore claim only:

1. The combination, in oil engines, of a primary combustion chamber attached to the main air intake valve and forming part thereof, the seat of the intake valve being provided with holes, which form a communication between the primary combustion chamber and the intake passage, when the valve is off its seat.

2. The combination in oil engines having a main air inlet valve, of a primary combustion chamber attached to the main air inlet valve and forming a part thereof, a hollow stem for said inlet valve open at the top through which fuel is supplied to said cylinder, a stationary bracket mounted on said engine, an extension carried by said bracket extending within said hollow valve stem and having an oil tight fit therein, a connection between said extension and a fuel tank, and a check valve within said connection.

3. A combination in an oil engine having a main air inlet valve, of a primary combustion chamber attached to said inlet valve and forming part thereof, a hollow stem for said valve through which fuel is supplied to said cylinder, and an automatically operati ing check valve having a restricted lift within said hollow stem.

4. A combination in an oil engine having a main air inlet valve, of a primary combustion chamber attached to said inlet valve and forming part thereof, a hollow stem for said valve through which fuel is supplied to said primary combustion chamber, an automatically operating check valve having a restricted lift within said hollow stem, and a means for adjusting the lift of said check valve.

5. In combination with a main air inlet valve for internal combustion engines of a primary combustion chamber carried thereby in constant communication with the combustion space of the engine, means for supplying predetermined quantities of liquid fuel to said primary combustion chamber, and means for scavenging said primary cylinder when said inlet valve is open.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ROBERT HOFSTETTER. [1.. s] Witnesses RUTH GIBBING, [L s] HENRY W. DUNAVAN. [n 5.] 

